define(function() {

	var lastTime = 0;
	var vendors = ['ms', 'moz', 'webkit', 'o'];

	for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
		window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
		window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame']
			|| window[vendors[x]+'CancelRequestAnimationFrame'];
	}

	if (!window.requestAnimationFrame) {
		window.requestAnimationFrame = function(callback, element) {
			var currTime = new Date().getTime();
			var timeToCall = Math.max(0, 16 - (currTime - lastTime));
			var id = window.setTimeout(function() {
				callback(currTime + timeToCall);
			}, timeToCall);
			lastTime = currTime + timeToCall;
			return id;
		};
	}

	if (!window.cancelAnimationFrame) {
		window.cancelAnimationFrame = function(id) {
			clearTimeout(id);
		};
	}

	return function(callback, delay) {
		var time;
		(function draw() {
			requestAnimationFrame(draw);
			var now = new Date().getTime(),
			dt = now - (time || now);
			time = now;
			callback(dt);
		})();
	};

});